Previously, processes for producing corresponding unsaturated nitrile by gas phase catalytic ammoxidation of propylene have been well known. However, a process has recently drawn attention, the process in which corresponding unsaturated nitrile is produced by gas phase catalytic ammoxidation using propane as a substitute for propylene. A large number of catalysts used have been proposed.
Patent Literature 1 discloses an ammoxidation catalyst for propane as a feedstock, the catalyst containing Mo, V, and Nb. With regard to this catalyst, it has been known that a calcination atmosphere is preferably kept under an inert gas atmosphere during a step of subjecting a catalyst precursor to calcination in view of catalytic performance.